The Cyclops Solar Solutions 2 W 12 V Amorphous Solar Panel Battery Trickle Charger can be use as portable power, back-up power, battery charger and a trickle charger. The possibilities are endless. You can link multiple like-units together for more output. This panel efficiently charges in all weather conditions including overcast weather and has a maximum charge up to 12 W/600 mAh per hour. It is designed for permanent or semi-permanent mounting. Solar power is clean and pollution-free and maintenance-free operation unlike gas generators. It prevents the natural voltage drain off batteries over time keeping your 12 V batteries charged up.